This patch reduces the keepalive threshold of WUSB host controllers from timeout/2 to timeout/3. The keepalive timer fires every timeout/2 ms, but due to rounding errors and jitter, the host may decide not to send a keepalive at timeout/2. By the time the next timer fires, a full timeout period may have expired causing the device to be disconnected without ever having been sent a keepalive. Changing the keepalive threshold to timeout/3 ensures that at least one keepalive will be sent before a device is disconnected. The patch also updates the code to use msecs_to_jiffies consistently.
Signed-off-by: Thomas Pugliese <[email protected]> diff --git a/drivers/usb/wusbcore/devconnect.c b/drivers/usb/wusbcore/devconnect.c index 1d36531..33a1278 100644 --- a/drivers/usb/wusbcore/devconnect.c +++ b/drivers/usb/wusbcore/devconnect.c @@ -455,8 +455,8 @@ static void __wusbhc_keep_alive(struct wusbhc *wusbhc) dev_err(dev, "KEEPALIVE: device %u timed out\n", wusb_dev->addr); __wusbhc_dev_disconnect(wusbhc, wusb_port); - } else if (time_after(jiffies, wusb_dev->entry_ts + tt/2)) { - /* Approaching timeout cut out, need to refresh */ + } else if (time_after(jiffies, wusb_dev->entry_ts + tt/3)) { + /* Approaching timeout cut off, need to refresh */ ie->bDeviceAddress[keep_alives++] = wusb_dev->addr; } } @@ -1062,7 +1062,7 @@ int wusbhc_devconnect_start(struct wusbhc *wusbhc) wusbhc->wuie_host_info = hi; queue_delayed_work(wusbd, &wusbhc->keep_alive_timer, - (wusbhc->trust_timeout*CONFIG_HZ)/1000/2); + msecs_to_jiffies(wusbhc->trust_timeout / 2)); return 0; diff --git a/drivers/usb/wusbcore/wusbhc.c b/drivers/usb/wusbcore/wusbhc.c index 0faca16..c35ee43 100644 --- a/drivers/usb/wusbcore/wusbhc.c +++ b/drivers/usb/wusbcore/wusbhc.c @@ -75,12 +75,11 @@ static ssize_t wusb_trust_timeout_store(struct device *dev, result = -EINVAL; goto out; } - /* FIXME: maybe we should check for range validity? */ - wusbhc->trust_timeout = trust_timeout; + wusbhc->trust_timeout = min_t(unsigned, trust_timeout, 500); cancel_delayed_work(&wusbhc->keep_alive_timer); flush_workqueue(wusbd); queue_delayed_work(wusbd, &wusbhc->keep_alive_timer, - (trust_timeout * CONFIG_HZ)/1000/2); + msecs_to_jiffies(wusbhc->trust_timeout / 2)); out: return result < 0 ? result : size; } -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
